Identification of actin-, alpha-actinin-, and vinculin-containing plaques at the lateral membrane of epithelial cells.
Identification of actin-, alpha-actinin-, and vinculin-containing plaques at the lateral membrane of epithelial cells.
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DOI：
10.1083/jcb.102.5.1843
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发表时间：
1986-05
期刊：
影响因子：
--
通讯作者：
Franz H
中科院分区：
文献类型：
--
作者：
Drenckhahn D;Franz H
在本文中，一种新的类型的斑点桥粒样连接（II型斑块）的描述是分散沿着整个侧质膜的大鼠和人的肠上皮。超微结构II型斑块不同于经典类型的上皮斑点桥粒（“粘着斑”，进一步表示为I型桥粒）的膜相关斑块材料的弱电子密度，协会的斑块与微丝，而不是中间丝，和可见性差的材料在整个细胞间隙。因此，II型斑块类似于粘连小带的横截面。免疫荧光显微镜研究进行了使用抗体的主要蛋白质与斑块的I型桥粒（桥斑蛋白I）和三个主要蛋白质位于斑块的小带粘附（肌动蛋白，α-辅肌动蛋白，和黏着斑蛋白）。沿着肠和前列腺上皮的侧表面观察到两种类型的斑块：（a）I型桥粒，其用抗桥粒斑蛋白标记，但不结合肌动蛋白、α-辅肌动蛋白和粘着斑蛋白的抗体，和（B）另一组类似大小的斑块，其结合肌动蛋白、α-辅肌动蛋白和粘着斑蛋白的抗体，但不用抗桥粒斑蛋白染色。用抗桥粒斑蛋白和抗α-辅肌动蛋白双标记的连续切片的三维计算机重建进一步证实了两种类型的斑块在空间上沿着侧质膜彼此完全分离沿着。计算机图形进一步揭示了含有肌动蛋白、α-肌动蛋白和黏着斑蛋白的斑块具有形成簇的趋势，这也是II型斑块的典型特征。有人建议，II型斑块代表斑点桥粒样细胞间连接，其中，像粘附小带，似乎是连接到肌动蛋白丝系统。由于II型斑块覆盖了相当大一部分的侧细胞表面，它们可能在控制细胞形状和细胞间粘附方面发挥特殊作用。
In this paper, a new type of spot desmosome-like junction (type II plaque) is described that is scattered along the entire lateral plasma membrane of rat and human intestinal epithelium. Ultrastructurally type II plaques differed from the classical type of epithelial spot desmosome ("macula adherens", further denoted as type I desmosome) by weak electron density of the membrane-associated plaque material, association of the plaques with microfilaments rather than intermediate filaments, and poorly visible material across the intercellular space. Thus, type II plaques resemble cross-sections of the zonula adherens. Immunofluorescence-microscopic studies were done using antibodies to a main protein associated with the plaques of type I desmosomes (desmoplakin I) and to the three major proteins located at the plaques of the zonula adherens (actin, alpha-actinin, and vinculin). Two types of plaques were visualized along the lateral surface of intestinal and prostatic epithelium: (a) the type I desmosomes, which were labeled with anti-desmoplakin but did not bind antibodies to actin, alpha- actinin, and vinculin, and (b) a further set of similarly sized plaques, which bound antibodies to actin, alpha-actinin, and vinculin but were not stained with anti-desmoplakin. Three-dimensional computer reconstruction of serial sections double-labeled with anti-desmoplakin and anti-alpha-actinin further confirmed that both types of plaques are spatially completely separated from each other along the lateral plasma membrane. The computer graphs further revealed that the actin-, alpha- actinin-, and vinculin-containing plaques have the tendency to form clusters, a feature also typical of type II plaques. It is suggested that the type II plaques represent spot desmosome-like intercellular junctions, which, like the zonula adherens, appear to be linked to the actin filament system. As the type II plaques cover a considerable part of the lateral cell surface, they might play a particular role in controlling cellular shape and intercellular adhesion.